Loader



Sept. .16 [1924.

1 5. c. PRATT LOADER Filed Sept. 30, 1922 ag'rneay sept. 1s 1924.' 1,508,857.

E. C. PRATT LOADER Filed sept. 3o, 1922 4 sheets-sheet 2 Patented Sept. 16, 1924.

. rasa? ERNEsT o. PRATT, on MINNEAPOLIS, MINNESOTA.

LOADER.

Application led September 30, 1922. Serial No. 591,440.

To all whom t may concern:

Be it known that I, ERNEST C. PRATT, a citizen of the United States, residing in Minneapolis, in the county of Hennepin and State of Minnesota, have invented a new and useful Loader, of which the following is a specification.

My invention relates to improvements in loaders.

Broadly its object is to provide a durable and eiicient loader particularly, though not exclusively, for mining operations, said loader being adapted to pick up loads of material, distribute and store the same temporarily and finally discharge the accumulated loads.

More specifically it is my object to supply a loader including a self-propelled truck carrying a shovel adapted to be directed into the material to be loaded by appropriately guiding said truck, also including a hopper to receive loads from the shovel, said hopper having a movable bottom for distributing the loads therein and ejecting the same therefrom, the bottom of the hopper and said shovel being operated by the truck propelling medium.

With the foregoing and other objects in view, which will appear in the following description, the invention resides in the novel combination and arrangement of parts and in the details of construction hereinafter described and claimed.

In the drawings, Fig. 1 is a side elevation of a loader embodying my invention; 'F ig. 2 is a plan View thereof; Fig. 3 is a similar view illustrating, particularly, the mechanism beneath the hopper, the shovel and hopper in this view being shown in dotted lines; Fig. 4 is a longitudinal, central, sectional view of the loader; Fig. 5 is a diagrammatical view of the parts whose coaction effects the automatic step by step movement of the conveyor and Fig. 6 is a similar view of the parts whose co-action results in automatically arresting the throw of the shovel at its upper extremity.

In the drawings, `wherein similar reference characters are employed to designate similar parts throughout the several views, A indicates a truck, B a hopper and C a shovel. The truck A is of the type which is limited in elevation and easily maneuvered.

It comprises a pair of endless treads l10, a truck frame 11, `a motor 12 geared to said treads and traction control and steering levers 13 and 14 all of usual construction. The hopper B includes sides 15, a combined end and chute 16 and a conveyor ZJ forming a movable bottom for the hopper'. Said sides 15 are pivoted at their forward ends on a horizontal shaft 17 carried transversely of the truck frame 11 at the forward end thereof. These sides 15 are rigidly joined by means of U-shaped tie brackets 18 and supply a frame-work for the conveyor structure. This structure includes end rollers 19 and 20 (F ig. L1) and intermediate rollers 21 all journaled between the sides 15. Anendless apron 22 turns upon said end rollers 19 and 20, its upper reach being supported between said rollers by the rollers 21.v De- I pending from a beam 23 on the under side of the hopper B is a threaded prop 24. A nut 25 on this prop has a universal bearing limit of travel where the contents of the y bucket fall by gravity, over the end 16, onto the head of the conveyor b. i Said end 16 reaches upwardly and forwardly fromv the front end of the apron 22 to the top ofthe guard 31 and, as above indicated, has the combined function as an end for the hopper B and as a chtite for directing material from the shovel C to the conveyor b.

A drive shaft 32 ('Figs. 3 and t), reaching forwardly from the motor 12, is geared through a worm 33 and worin wheel 34 with a composite counter shaft structure D mounted transversely of the frame members 11 of the truck A. Saidcounter shaft structure is of usual design and while it is not illustrated in elaborate detail its construction will be understood from a brief description in connection with the drawings, particu- 75 on a beam 26 on the truck frame 11and larly Figs. 3 and 4. Said structure D includes a driving shaft liXed to the worm wheel 34 and reaching from. either side thereof, also driven sleeves 36 and 37 on said driving shaft. Clutch sets (Z, d ot ordinary design and including` the usual shifter yokes 38, 33l are respectively interposed between the sleeves 36 and 37 and the driving shatt 35 of the counter shaft structure D. A rockshatt 39 extending transversely ot the truck A rockably carries a sleeve 40 having an upright hand lever 4l at its outer end and an upright arm 42 at the inner end thereof. A link 43 joins said arm 42 with an arm 44 of a bell crank e on the truck trame, the second arm of said crank comprising the shifter .yoke 33 of the clutch set (Z. A sprocket wheel 45 on the sleeve 36 is connected through a sprocket chain 46 with. the member 47 ot a dual idler sprocket f journaled on the shaft 17 that supplies the pivotal support for the hopper B. The second member 43 (Fig. 2) ot the dual sprocket 7 is connected through a sprocket chain 49 with a sprocket wheel 50 on the driving roller 2O ot the conveyor b. With the motor l2 in motion and the members of the clutch set (Z disengaged, the conveyor o remains at rest. Following a pull upon the lever 4l, the members of said clutch set are engaged whereupon the roller 2O is turned in a direcm tion. to drive the apron 22 in a direction carrying its upper reach rearwardly.

rlhe loader is maneuvered to lill the shovel C, said shovel being 'thereafter elevated to discharge the contents thereof into the 'front oi the hop ier B. 'lhe mechanism for raising said shovel includes a pair of cables 51 reaching from the forward ends of the beams 29 over sheaves 52 on the sides ot the hopper B to winding drums 53 on adrum shaft 54 journaled transversely of the truck. A sprocket 55 on the drum shaft 54 is connected through a chain 56 with a sprocket 57 on the sleeve 37 ot the counter shaiit structure D. rlhe shifter yoke 33 comprises one arm of a bell crank e', the second arm 53 thereof being joined through a link 59 with an arm 6() on the rock-shalt 39 above mentioned. This rock-shaft has a hand lever Gl thereon in close proximity to the hand lever 4l. A pull upon the lever 6l, engages the members of the clutch set al and results in turning the drums 53 and in elevating the shovel C through the winding oit the cables 5l upon said drums. By releasing or pushing said lever 61 forward, the members of the clutch set d are disengaged, the shovel C being then free to tall by gravity. To control the movement ot the shovel C in its tall, l supply braking mechanism for the drum shaft 54, the same including a rock-shaft 62 (Figs. l and having a pedal 63 at one end thereot and an arm ('54 at the other, said arm being joined through a link 65 with a brake band 66 oit ordinary design encircling said drum shaft lo prevent an operator from accidentally raising the shovel too tar and thereby imposing unnecessary strains upon the device, as by the pulling of the bea-ms 29, 29 against the sheaves 52, l supply an automatic trip for disengaging the shovel ele vating mechanism trom the source of power. 'lhis trip includes an arm or extension 67 (Figs. and 6) on the end ot the shovel beam 29 and a lever 63 on the rock-shaft 39, said arm G7 being arranged to strike the lever 63 and turn the rock-shalt 39, when the shovel C reaches position ot discharge, the turning oit said rock-shaft operating to free the shovel from the source of power in the manner attained by turning said shaft 39 through the medium ot the hand lever Gl.

Means including a lever 69 (Figs. l and and cam g provide tor automatically advancing the conveyor Z) upon each operation ot the shovel C, whereby it is unnecessary for the operator to personally attend to the step by step advancement ot the conveyor during the loading ot the hopper B. Said lever 69 reaches upwardly and forwardly trom the sleeve 40, the upper end of said lever having a cam suriace 69 the 1eon. The cam g comprises an arm 7 O pivoted on the Yliront axle 30 ot the truck A and a quadrant 7l integal with said arm, said quadrant being held in selected angular relation with respect to the shovel beam 29 by means ot a binding bolt 72 anchored in said beam and reaching through a slot 73 in the quadrant. The cam g is preferably set so that the arm 7 O willthrow the lever 69 rearwardly and start the conveyor o as the shovel 'C swings into its elevated position ot discharge. lWith this adjustment ot said cam, the upper reach ot the apron 22 starts and moves rearwardly as material falls trom the shovel, over the chute 16, onto said apron, said movement oi said apronbeing arrested by the lowering ot the shovel C. llrom the foregoing, it will be understood, that the conveyor is shifted a step upon each operation ot the shovel, the movement ot the conveyor being initiated as the shovel moves into discharging position and conh tinuing until said shovel falls from suoli position. ln normal operation, each automatic distributing step oit' the apron 22 continues temporarily alter the shovel is emptied and until it reaches depressed position wherein the cam g and lever 69 are disengaged. rThis movement ot the apron 22 after the flow of material thereto has ceased results in presenting a clear portion thereof tor the reception ot the initial and greater part ot the nent shovel load, the balance of which is distributed on said apron during the beginning of its next distributing step.

An operator on the seat 74 advances, reverses and turns the loader to load the shovel C and to locate the rear of the hopper B over a receptacle, chute, conveyor or the like for receiving the contents of the hopper, the desired elevation of the delivery end of said hopper being attained by suitable adjustment of the nut 25. A pull upon the lever 61 results in elevating the shovel C, the lifting thereof being automatically arrested when the shovel reaches its position of discharge. 'Said shovel C being arrested in its upward throw by disconnecting the same from the motor l2, is held in its position of discharge and lowered under control of the operator through the medium of the pedal 63 and associated braking mechanism. In the upper part of the cycle of said shovel, the conveyor Z) is advanced a step automatically, as hereinbefore eX- plained, thus causing successive shovel loads to be distributed over the bottom of the hopper B. Having located the delivery end of the hopper over the desired receptacle, the operator pulls upon the lever 4l, causing a continuous movement of the conveyor Z) and the resultant discharge of the contents of the hopper B intov said receptacle. This continuous ejecting movement of said conveyor is arrested upon releasing said lever 41. The emptying of the hopper B also may be accomplished by holding the shovel C in position of discharge. This is not particularly advantageous in all cases, but in certain instances it saves time and the trouble of manipulating the lever 61.

Changes in the specific form of my invention, as herein disclosed, may be made within the scope of what is claimed without departing from the spirit of my invention.

Having described my invention, what I claim as new and desire to protect by Letters Patent is:

l. In a loader of the class described, a truck, a conveyor on the truck for receiving, temporarily storing and discharging material, a shovel for picking up loads and discharging the same on said conveyor, a source of power for propelling the truck, op-A erating the shovel and driving the conveyor and means for automatically causing said conveyor to advance when the shovel is positioned to empty its contents, whereby material falling from the shovel is spread upon said conveyor.

2. In' a loader ofthe class described, a truck, a conveyor carried on the truck, a shovel on said truck movable between receiving positions and elevated position of discharge above one end of the conveyor, a

source of power for propelling the truck, elevating the shovel and driving the conveyor and means for automatically connecting the conveyor with said source of power,

upon each operation of the shovel, to shift 'l receiving end of the conveyor, a source of power, a power train associated therewith and with said conveyor forl driving the latter and dual actuating mechanisms incorporated in said power train, one mechanism being adjustably associated with the shovel and adapted upon each operation thereof to be tripped thereby and to cause said conveyor to be geared with said source of power and variably advanced a step preparatory to receiving a fresh charge from said shovel, the second mechanism being manually operable to effect continuous movement of the conveyor and the resultant discharge of the material accumulated thereon.

4L. In a loader of the class described, a truck, a conveyor carried on the truck for receiving, temporarily, storing and discharging material therefrom, a shovel on said truck movable between receiving positions and elevated position of discharge above the receiving end of the conveyor, a source of power, a power train associated therewith and with said conveyor for driving the latter and dual actuating mechanisms incorporated in said power train, one mechanism being associated with the shovel and adapted upon each operation thereof to be tripped thereby and to cause said conveyor to be geared with said source of power and advanced a step preparatory to receiving a fresh charge from said shovel, the second mechanism being manually operable to effect continuous movement of the conveyor and the resultant discharge of the material accumulated thereon.

5. In a loader of the class described, a truck, a conveyor carried on the truck, a shovel on said truck movable between receiving positions and elevated position of discharge above one end of the conveyor, asource of power for elevating the shovel, a power train between said source of power and shovel, manually operated means incorporated in said power train for actuating the same to cause the elevation of said shovel and an adjustable tripping device associated with said shovel for automatically interrupting the application of lifting power to the shovel at predetermined elevation thereof.

6. In a loader of the class described, a truck, a conveyor carried on the truck, a shovel on said truck movable between receiving positions and elevated position of discharge above one end of the conveyor, a so'urcevof power for elevating the Shovel, a power train between said source of power and shovel, manually operated means incorporated in said power train for actuating' the same to cause the elevation of said shovel and a tripping device associated with said shovel for automatically interrupting the application of lifting power to the shovel at predetermined elevation thereof. 10

In testimony whereof, I have signed my name to this specification.

ERNEST C. PRATT. 

